Furnace



FURNACE Filed July 6, 1928 2 Sheets-Sheet l y' ATTORNEYS E. G. BAILEYJune 14, 1932.

FURNACE Filed July 6, 1928 2 Sheets-Sheet /i iNvEN/TOR I AATTQRNEYPatented June 14, 1932 UNITED STATES PATENT OFFICE ERVIN G. BAILEY, OFEASTON, PENNSYLVANIA, ASSIGNOR TO FULLER LEHIGH COM- PANY, F FULLERTON,PENNSYLVANIA, A CORPORATION 0F DELAWARE FURNACE Application. filed July6, 1928.

My invention more particularly relates to a furnace adapted to burnfinely divided anthracite or other fuel, though it will be understoodthat it is not necessarily limited thereto. The present invention isclosely related to the invention disclosed and claimed in my copendingpatent application, Serial No. 290,807,1fi1ed July 6, 1928.

My invention will best be understood by 0 reference to the accompanyingdrawings, in which Fig. 1 is a vertical sectional view in partdiagrammatic, through a furnace embodying my invention, Fig. 2 is asection, likewise diagrammatic in part, at right 5 angles to Fig. 1,Fig. 3 is a fragmentary plan View of a stoker adapted for use in myinvention, and Fig. 4 is a side view of the parts shown in Fig. 3.

Like reference characters indicate like parts throughout the drawings.

Referring now to the drawings, and 11 indicate the front and rear walls,respectively, of a furnace chamber, the lower portion of the wallssloping downwardly and inwardly at 12 and 13 to form a V-shaped lowerportion. The inclined wall 12 is preferably cooled by cooling tubes 14connected to headers 15 and 16 which may, in turn, be connected into theboiler circulation in a known manner. Similarly, the wall 13 ispreferably cooled by tubes 17 connected at their lower and upper ends toheaders 18 and 19, respectively. The headers 19 may conveniently be Vsupported by U-shaped straps 20, which are secured to fixed members 21as shown in Fig. 1. Side walls for the furnace are illustrated at 22 and23 (Fig. 2).

Anthracite or other fuel preferably crushed to comparatively small size,for example a quarter of an inch in diameter or less, is introducedpreferably into the upper portion of the furnace chamber 24 through afeeder pipe or feeder pipes 25 through an i opening 26 which is shown asformed in an arch 27 extending across the upper part of a portion of thefurnace chamber.

At the bottom of the furnace is located an ash conveyor of the chaingrate type indicated generally at 28. The ash conveyor of the chaingrate type comprises the usual Serial No. 290,808.

sprocket wheels 29, which receive the chain in a well known manner. Airenters a chamber 30 beneath ythe ash conveyor Vby means of a duct 31,the flow of air into which is controlled by a damper or dampers 32 whichmay, if desi-red, be manually operated. The end ofthe chamber 30 ispreferably sealed by a damper 33 as best shown in Fig. l, while theright-hand portion of the chamber is-enclosed by a portion 34 of thecasing, the upper portion of the ash conveyor being substantially sealedagainst the walls 17.

The links 35 fof the ash conveyor are spaced apart by ribs or lugs 36,which extend vertically along the links and provide spaces 37therebetween through which the air entering from the duct 31 isintroduced to the'furnace and with sufficient velocity to cause the fuelof the proper degree of ineness to 4rise and float in the furnace, thefuel being maintained insuspension, Ipractically none of it everreaching the conveyor, and even if it does reach the conveyor, thehigher velocity at the conveyor itself would cause the fuel to rise, the`heavier particles naturally iioating nearer the bottom of the furnacechamber while the lighter particles rise higher where the velocity ofthe'air and rising gases is lower. In operation, some fuel may work offto one side and drop onto the V-shaped walls of the furnace, float downthe smooth, cooled, inclined fioor, until it reaches the high velocityzone, where it is again thrown up into the furnace. This action resultsin keeping the fuel in what has the appearance of being a boiling,seething mass, and continually in motion, with the air for combustioncontinually contacting the surface of each particle, thereby producing avery rapid rate of combustion. There is a decided tendency to unify thedensity of fuels throughout the width and length of this zone, so thatthere are no thick or thin zones where excess or deficiency of air willresult.

Another phenomenon which takes place in a furnace of this kind is thecoagulation of the particles of ash after the carbon has been burnedfree from them. These particles get in a semi-fused state, and when onecontacts with another they cement together forming a nodule of ashconsiderably larger than any of the particles of coal originally fed tothe furnace. These larger particles finally grow until they are' heavyenough to fall down through the high velocity zone and rest upon 5 theconveyor, and they are then carried by the conveyor to the ash pit 38,the bottom of which is preferably closed by sloping walls 39 and 40 andin the bottomportion of which is preferably located a screw conveyor 4110, whichV may be operated from a motor 42 through a suitable reductiongearing 43.

The height of the ash conveyor may be ad- Y, j usted by means ofhydraulic lifts 44 or any other suitable device. Y Y Y p y I claim: f

1;v In a furnace, walls sloping downwardly and inwardly, meansforprojecting pulverized fuel downwardly, anash conveyor in the bottomof said furnace having openings therein, water tubes in said wallsproviding a coolingzone above said conveyor, and means for keeping fuelfrom said conveyor, said means comprising a duct for conveyingcombustion air under pressure beneath said conveyor, said conveyorserving merely for removal of nodules of ash to an ash-pit.4

2. In a furnace, walls slopingv downwardly and inwardly, means forprojecting pulverized fuel downwardly, an ash conveyor in the bottom vofsaid furnace having openings therein, water tubespin said vwallsproviding a cooling zone above said conveyor, and an airboX beneath saidconveyor for I projecting combustion air upwardly through the openingsin said conveyor,all of the fuel being burned in suspension above saidconveyor and said conveyor serving merely for removal of nodules ofv ashtoan ash-pit. r i i 3. In a furnace, walls sloping downwardly andinwardly, means for projecting pulverized fuel downwardly,an ashconveyor in the bottomof said furnace'having openings vtherein, andwater tubes in' said wall providing a cooling zone above said conveyor,in combination with an air-box beneath said conveyor for projectingcombustion air upwardly through the openings in said conveyor, and anash-pit beneath Ysaid conveyor and said air-box, all of the fuel beingburned in suspension above said conveyor, said conveyor serving merelyfor removal of nodules of ash from said furnace to said ash-pit.

ERVIN G. BAILEY.'

